Practice MCQ Questions and answers on Physics-GK

Resolution is an umbrella term that describes the detail an image holds. The term applies to raster digital images, film images, and other types of images. The display resolution of a digital television, computer monitor or display device is the number of distinct pixels in each dimension that can be displayed.

A microwave is the fastest communication channel whereas optical fiber is a way of transferring data not a way of communication.

The layer of atmosphere used for radio-wave transmission is Ionosphere.

High frequency (HF) is the ITU designation for the range of radio frequency electromagnetic waves (radio waves) between 3 and 30 megahertz (MHz). It is also known as the decameter band or decameter wave as its wavelengths range from one to ten decameters (ten to one hundred meters).

Total internal reflection is the basic concept behind the optical fiber. Optical fiber employs the transmission of light down fibers of plastic or glass. Because the fibers are thin, light entering one is likely to strike the inside surface at an angle greater than the critical angle and, thus, be totally reflected. In fact, most fibers have a varying refractive index to allow more light to be guided along the fiber through total internal refraction.

The path that data takes from source to destination is called a Channel. A channel is a communication medium. A channel has a certain capacity for transmitting information. The Capacity of a communication channel is measured in Band with.

The frequency used in TV and radar system lies in UHF.

The microwaves are preferred in order to communicate with the artificial satellites which are orbiting the earth at a particular height from the surface of the earth. The microwaves are preferred because they can penetrate through the Earth's atmosphere very easily and reach the target satellite.

A modem – a portmanteau of "modulator-demodulator" – is a hardware device that converts data from a digital format, intended for communication directly between devices with specialized wiring, into one suitable for a transmission medium such as telephone lines or radio.

Communication satellites are located in Ionosphere.